INDUSTRIAL AND ENGINEERING CHEMISTRY
November, i923
No effort was made, however, to identify it accurately. The yields obtained by the use of phosphoric acid were surprisingly low. Kressmanns reports a yield of sugar of 19.38 per cent and 15.66 gallons of 95 per cent alcohol per ton. Sulfanilic acid also gave yields somewhat higher than were obtained in the blank.
- -
1165
using 7.5 per cent sulfuric acid cooking for 15 minutes and varying the pressure from 80 pounds in Cook l l O c to 125 pounds in Cook 116c. This series of experiments gave the highest yields of alcohol obtained heretofore on white spruce sawdust, a yield of 29.05 gallons of 190 proof or 27.6 gallons of absolute alcohol being obtained-a 29 per cent increase over the blank The results of these experiments are shown in Table V. TABLEV H?so4
so$ Y?
Y
2Q
Total Percent Pressure Per cent ReTime Lhs./Sq. of Dry ducing Wood Sugars Min. In. In
25-
Cook No.
20-
llOr lllc 112r 116c
-
-
i? 15-
16 15 15 15
80 100 120 125
7.5 7.5 7.5 7 5
Gallons Per cent Alcohol Sugars Alcohol per FermentYield Ton of able Percent DryWood
21 44 22.51 23.60 22 29
13 15 17 16
40 12 80 05
6.85 7.72 9 11 8.11
20.70 23.40 27.60 24.55
%
6$
1 A v e.r.~
-b
2
T
Per Cenf - YO
Kreasmann studied the effect of sulfuric acid by varying the concentration up to 5 per cent. It was now decided to continue increasing the acid Concentration until the fermentable sugars showed a decided decrease. To complete the study the residues from each cook were analyzed for cellulose by the Cross and Bevan method, in order to determine the extent to which decomposition occurs during the treatment. The concentration of sulfuric acid was varied between 5 and 30 per cent, with the results given in Table 111. -------Per Grams of HnSOi Yotal per 100 Reducing of Dry Wood Sugars
5 10 15 20 30
TABLE I11 cent of Original Dry Wood Fermentable Sugars
16.29 18.00 16.10 13.67 2.70
21.98 21.54 19.71 16.00 7 28
---
Cellulose Unchanged
Cellutose Removed
31.7 20.46 13.71 8.95 2.14
26.5 37.74 44.50 49.25 66.06
It will be noticed that after a maximum is reached a fairly uniform decrease of total reducing sugars and fermentable sugars occur$, while the cellulose removed increases very rapidly. Since. the ratio of sugar to cellulose removed increases with the concentration of acid, it appears that the sugars are destroyed more rapidly than the cellulose is hydrolyzed. These changes are shown somewhat more clearly in Fig. I. The yield of fermentable sugar having been materially ' sed by the use of 10 per cent sulfuric acid for 15minutes, nd set of experiments was run in which the acid concentration was held constant at 10 per cent but the time factor was varied. Here again the yield of fermentable sugars passed through a maximum, although the subsequent drop was gradual. The maximum in this series of experiments came with an acid concentration of 10 per cent and a cook of 10 minutes' duration at 115 pounds' steam pressure (175" C.). The results may be seen in Table IV. TABLE
No.
104c 1056 Q9c 108c l06c 109,
5 10 15 15 20 25
10 10 10 10 10 10
2 L 54 23.98 21,54 22.85 21.42 21.92
13.50 17.02 16.54 16.64 15.85 16.18
6.88 8.67 8.45 8.47 8.10 8.27
20.80 26.30 25.60 25.67 24.55 25.05
Having varied acid and time factors, the pressure factor was now studied, and a series of experiments was performed 8
U. S. Dcpt. Ag7., Bull. 988.
2M 3M 4M 5M 6M
15 15 10 15 15
115.1 115.1 115.1 54.6 19.6
175 175 175 150 125
H2SOa Concentration G./Cc.
0.0125 0.0125 0.0125 0.0125 0.0315 0.0250
---Before Cook
Per cent Mannose--After Decom- UndecomCook Dosed Dosed
3.644 3.752 1.9152 1.9180 1.882 1.908
1.54 3.588 3.786 -0.91 1.156 24.55 1.312 14.50 1.403 6.82 1.489 2.45
98.46 100.96 75.48 85.5 93.18 97.55
Since these results indicate a marked decomposition of the sugars under rather extreme conditions, the question naturally arose as to what sugars were the most susceptible to variations of conditions. Neuman4 studied the decomposition of glucose by dilute acid at different temperatures and concluded that 175' C. marked the "critical point" beyond which it is useless to investigate the production of sugars. Since mannose constitutes a considerable proportion of the sugars that result from the hydrolysis of softwoods, it was desiraf o r 15rntnufes la) ble tormeat this series of experiments upon this sugar. Theresults p 2o obtained are given in a Table VI and Fig. 11. 9 In the case of mannose 3 /5 1.25 per cent sulfuric acid was used as com- 8C pared with 1.0 per cent and 1.5 per cent * 10 in Neuman's work. The decomposition of c mannose under similar conditions is ap5 parently the same as that of glucose, since the curve showing the rate of decomposi100 125 150 / 75 tion parallels those of Temo 'C glucose.
E
4
4
Dissertation, Dresden, 1910, p. 31.
IV
in Total Percent Alcohol Pressure Per cent Per cent Sugars Alcohol per Ton Time Lbs./Sq. of D r y Reducing Ferment- Yield of Dry Min. In. Wood Sugars able P e r c e n t Wood
115 115 115 115 115 115
aer
age TcmPressure peraCook Time Lbs./Sq. ture No. Min. In. C. 1M 15 19.6 125
5 -
Cook
TABLE VI
Aver-
'0
.
Report of Committee on Fertilizer Legislation
A report of the Committee on Fertilizer Legislation of the Division of Fertilizer Chemistry of the AMERICAN CHEMICAL SOCIETYwas presented a t the Milwaukee meeting by J. E. Breckenridge. This report consisted of a review of the fertilizer legislation of importance enacted during the past year, referring particularly to the new Florida law relating to the guarantee of available and soluble nitrogen, and to the new North Carolina law pertaining to the showing of the mineral and organic nitrogen on the source tags.
